This invention is directed to a guiding catheter for negotiating a tortuous non-linear conduit and to a method for its use.
In many medical procedures, such as percutaneous transluminal angioplasty, it is necessary to advance a catheter through a narrow tortuous blood vessel without damaging the endothelium. A variety of systems are used, such as guide wires, for example, see U.S. Pat. No. 4,436,017, guiding catheters, for example, see U.S. Pat. No. 3,773,034, and everting catheters, for example, see U.S. Pat. No. 4,437,857. A difficulty with commonly used guiding systems is that the procedure is time consuming and requires great skill on the part of the surgeon. Also many systems require the use of a large number of pre-bent guiding tips for accommodating different changes in the path of the vascular system.
The guiding, i.e. steerable, catheter disclosed in U.S. Pat. No. 3,773,034 has at its distal end a steerable tip formed of a flexible, thin, stretchable and contractible material. As the pressure of fluid within the distal end is varied, the steerable tip axially elongates or contracts. One longitudinally extending portion of the tip is restrained from stretching so that an increase in pressure on the fluid in the catheter results in bending of the steerable tip. The restraint may be the walls of the blood vessel or other channel in which the catheter is being inserted or an axially restraining means in the wall of the catheter tip. One disadvantage of this catheter is that if there is a constriction, e.g. caused by the blood vessel walls or improper positioning of the catheter, increased fluid pressure may not cause the desired bending. The degree of bending will be unknown by the person inserting the catheter who will be able to note only the increase in fluid pressure.
There is a need for a device for accessing remote regions of the vascular system without problems associated with current devices.